I understand that it's not considered possible (or at least practical)
to test all package upgrades on all platforms. However, certain
packages have a large number of dependencies. Take glib2 for example.
Likely as a result of an upgrade from 2.28.8 to 2.30.2 on 29 Jan 2012,
it now doesn't build on DragonFly resulting in 1849 breakages (1760
directly).

Would it be a good idea to identify packages like this one that have a
large number of direct dependencies (say > 100) and require that any
version upgrade be tested on a standard set of platforms before getting
committed?

Or to put it another way: Would this glib2 version upgrade have been
committed if it were known that it didn't build on DragonFly? Hopefully
the answer is "no". I think this kind of breakage is avoidable. Is
this something we could discuss?